hey gang, apologies for bring this thread back from the dead, I have this lever on the side of my gas fireplace as well. I also have a much larger lever at the top of the fireplace to open the flute. Wanted to know what position I should have the "outside air control" valve set to (the little lever on the side, not the flute), open or closed, when I have a fire going. Reading what Joe wrote, seems I should have it open, but not sure, the posts are kind of confusing me. Thanks.